Peter, Rex, I like the idea of trimming the adapter and bellhousing flange. I had forgotten that we used to do that on roundy rounders!
Rex, I agree that sitting the engine, so that the lowest part is between the frame rails would be optimum. I don't, however, like the high center of gravity of the engine, when it sits that way. Remember, this is why I gave up the Coupe class, and went with the setback. In Comp Coupe, there will be a bellypan, so that should help some.
Maybe I'm being over cautious, having never ran on the salt. I'm trying to avoid spinning, and if I do, I want the CG as low as possible. It is entirely possible/probable, that after running this year, I will rethink this whole setup, and do as you suggest next year!
Please keep the suggestions and critiques coming, as they are very helpful!